media: i2c: ov9282: Add support for 8bit readout

The sensor supports 8 or 10 bit readout modes, but the
driver only supported 10 bit.

Add 8 bit readout.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/i2c/ov9282.c

@@ -21,6 +21,10 @@
 #define OV9282_MODE_STANDBY	0x00
 #define OV9282_MODE_STREAMING	0x01
 
+#define OV9282_REG_PLL_CTRL_0D	0x030d
+#define OV9282_PLL_CTRL_0D_RAW8		0x60
+#define OV9282_PLL_CTRL_0D_RAW10	0x50
+
 #define OV9282_REG_TIMING_HTS	0x380c
 #define OV9282_TIMING_HTS_MAX	0x7fff
 
@@ -48,6 +52,10 @@
 /* Group hold register */
 #define OV9282_REG_HOLD		0x3308
 
+#define OV9282_REG_ANA_CORE_2	0x3662
+#define OV9282_ANA_CORE2_RAW8	0x07
+#define OV9282_ANA_CORE2_RAW10	0x05
+
 #define OV9282_REG_TIMING_FORMAT_1	0x3820
 #define OV9282_REG_TIMING_FORMAT_2	0x3821
 #define OV9282_FLIP_BIT			BIT(2)
@@ -63,8 +71,10 @@
 #define OV9282_NUM_DATA_LANES	2
 
 /* Pixel rate */
-#define OV9282_PIXEL_RATE	(OV9282_LINK_FREQ * 2 * \
-				 OV9282_NUM_DATA_LANES / 10)
+#define OV9282_PIXEL_RATE_10BIT		(OV9282_LINK_FREQ * 2 * \
+					 OV9282_NUM_DATA_LANES / 10)
+#define OV9282_PIXEL_RATE_8BIT		(OV9282_LINK_FREQ * 2 * \
+					 OV9282_NUM_DATA_LANES / 8)
 
 /*
  * OV9282 native and active pixel array size.
@@ -140,6 +150,7 @@ struct ov9282_mode {
  * @again_ctrl: Pointer to analog gain control
  * @vblank: Vertical blanking in lines
  * @cur_mode: Pointer to current selected sensor mode
+ * @code: Mbus code currently selected
  * @mutex: Mutex for serializing sensor controls
  * @streaming: Flag indicating streaming state
  */
@@ -158,9 +169,11 @@ struct ov9282 {
 		struct v4l2_ctrl *exp_ctrl;
 		struct v4l2_ctrl *again_ctrl;
 	};
+	struct v4l2_ctrl *pixel_rate;
 	u32 vblank;
 	bool noncontinuous_clock;
 	const struct ov9282_mode *cur_mode;
+	u32 code;
 	struct mutex mutex;
 	bool streaming;
 };
@@ -178,7 +191,6 @@ static const s64 link_freq[] = {
  */
 static const struct ov9282_reg common_regs[] = {
 	{0x0302, 0x32},
-	{0x030d, 0x50},
 	{0x030e, 0x02},
 	{0x3001, 0x00},
 	{0x3004, 0x00},
@@ -516,19 +528,29 @@ static int ov9282_write_regs(struct ov9282 *ov9282,
  * ov9282_update_controls() - Update control ranges based on streaming mode
  * @ov9282: pointer to ov9282 device
  * @mode: pointer to ov9282_mode sensor mode
+ * @fmt: pointer to the requested mode
  *
  * Return: 0 if successful, error code otherwise.
  */
 static int ov9282_update_controls(struct ov9282 *ov9282,
-				  const struct ov9282_mode *mode)
+				  const struct ov9282_mode *mode,
+				  const struct v4l2_subdev_format *fmt)
 {
 	u32 hblank_min;
+	s64 pixel_rate;
 	int ret;
 
 	ret = __v4l2_ctrl_s_ctrl(ov9282->link_freq_ctrl, mode->link_freq_idx);
 	if (ret)
 		return ret;
 
+	pixel_rate = (fmt->format.code == MEDIA_BUS_FMT_Y10_1X10) ?
+		OV9282_PIXEL_RATE_10BIT : OV9282_PIXEL_RATE_8BIT;
+	ret = __v4l2_ctrl_modify_range(ov9282->pixel_rate, pixel_rate,
+				       pixel_rate, 1, pixel_rate);
+	if (ret)
+		return ret;
+
 	hblank_min = mode->hblank_min[ov9282->noncontinuous_clock ? 0 : 1];
 	ret =  __v4l2_ctrl_modify_range(ov9282->hblank_ctrl, hblank_min,
 					OV9282_TIMING_HTS_MAX - mode->width, 1,
@@ -698,10 +720,16 @@ static int ov9282_enum_mbus_code(struct v4l2_subdev *sd,
 				 struct v4l2_subdev_state *sd_state,
 				 struct v4l2_subdev_mbus_code_enum *code)
 {
-	if (code->index > 0)
+	switch (code->index) {
+	case 0:
+		code->code = MEDIA_BUS_FMT_Y10_1X10;
+		break;
+	case 1:
+		code->code = MEDIA_BUS_FMT_Y8_1X8;
+		break;
+	default:
 		return -EINVAL;
-
-	code->code = MEDIA_BUS_FMT_Y10_1X10;
+	}
 
 	return 0;
 }
@@ -721,7 +749,8 @@ static int ov9282_enum_frame_size(struct v4l2_subdev *sd,
 	if (fsize->index >= ARRAY_SIZE(supported_modes))
 		return -EINVAL;
 
-	if (fsize->code != MEDIA_BUS_FMT_Y10_1X10)
+	if (fsize->code != MEDIA_BUS_FMT_Y10_1X10 &&
+	    fsize->code != MEDIA_BUS_FMT_Y8_1X8)
 		return -EINVAL;
 
 	fsize->min_width = supported_modes[fsize->index].width;
@@ -737,15 +766,17 @@ static int ov9282_enum_frame_size(struct v4l2_subdev *sd,
  *                            from selected sensor mode
  * @ov9282: pointer to ov9282 device
  * @mode: pointer to ov9282_mode sensor mode
+ * @code: mbus code to be stored
  * @fmt: V4L2 sub-device format need to be filled
  */
 static void ov9282_fill_pad_format(struct ov9282 *ov9282,
 				   const struct ov9282_mode *mode,
+				   u32 code,
 				   struct v4l2_subdev_format *fmt)
 {
 	fmt->format.width = mode->width;
 	fmt->format.height = mode->height;
-	fmt->format.code = MEDIA_BUS_FMT_Y10_1X10;
+	fmt->format.code = code;
 	fmt->format.field = V4L2_FIELD_NONE;
 	fmt->format.colorspace = V4L2_COLORSPACE_RAW;
 	fmt->format.ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
@@ -775,7 +806,8 @@ static int ov9282_get_pad_format(struct v4l2_subdev *sd,
 		framefmt = v4l2_subdev_get_try_format(sd, sd_state, fmt->pad);
 		fmt->format = *framefmt;
 	} else {
-		ov9282_fill_pad_format(ov9282, ov9282->cur_mode, fmt);
+		ov9282_fill_pad_format(ov9282, ov9282->cur_mode, ov9282->code,
+				       fmt);
 	}
 
 	mutex_unlock(&ov9282->mutex);
@@ -797,6 +829,7 @@ static int ov9282_set_pad_format(struct v4l2_subdev *sd,
 {
 	struct ov9282 *ov9282 = to_ov9282(sd);
 	const struct ov9282_mode *mode;
+	u32 code;
 	int ret = 0;
 
 	mutex_lock(&ov9282->mutex);
@@ -806,7 +839,12 @@ static int ov9282_set_pad_format(struct v4l2_subdev *sd,
 				      width, height,
 				      fmt->format.width,
 				      fmt->format.height);
-	ov9282_fill_pad_format(ov9282, mode, fmt);
+	if (fmt->format.code == MEDIA_BUS_FMT_Y8_1X8)
+		code = MEDIA_BUS_FMT_Y8_1X8;
+	else
+		code = MEDIA_BUS_FMT_Y10_1X10;
+
+	ov9282_fill_pad_format(ov9282, mode, code, fmt);
 
 	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
 		struct v4l2_mbus_framefmt *framefmt;
@@ -814,9 +852,11 @@ static int ov9282_set_pad_format(struct v4l2_subdev *sd,
 		framefmt = v4l2_subdev_get_try_format(sd, sd_state, fmt->pad);
 		*framefmt = fmt->format;
 	} else {
-		ret = ov9282_update_controls(ov9282, mode);
-		if (!ret)
+		ret = ov9282_update_controls(ov9282, mode, fmt);
+		if (!ret) {
 			ov9282->cur_mode = mode;
+			ov9282->code = code;
+		}
 	}
 
 	mutex_unlock(&ov9282->mutex);
@@ -838,7 +878,8 @@ static int ov9282_init_pad_cfg(struct v4l2_subdev *sd,
 	struct v4l2_subdev_format fmt = { 0 };
 
 	fmt.which = sd_state ? V4L2_SUBDEV_FORMAT_TRY : V4L2_SUBDEV_FORMAT_ACTIVE;
-	ov9282_fill_pad_format(ov9282, &supported_modes[DEFAULT_MODE], &fmt);
+	ov9282_fill_pad_format(ov9282, &supported_modes[DEFAULT_MODE],
+			       ov9282->code, &fmt);
 
 	return ov9282_set_pad_format(sd, sd_state, &fmt);
 }
@@ -903,7 +944,17 @@ static int ov9282_get_selection(struct v4l2_subdev *sd,
  */
 static int ov9282_start_streaming(struct ov9282 *ov9282)
 {
+	const struct ov9282_reg bitdepth_regs[2][2] = {
+		{
+			{OV9282_REG_PLL_CTRL_0D, OV9282_PLL_CTRL_0D_RAW10},
+			{OV9282_REG_ANA_CORE_2, OV9282_ANA_CORE2_RAW10},
+		}, {
+			{OV9282_REG_PLL_CTRL_0D, OV9282_PLL_CTRL_0D_RAW8},
+			{OV9282_REG_ANA_CORE_2, OV9282_ANA_CORE2_RAW8},
+		}
+	};
 	const struct ov9282_reg_list *reg_list;
+	int bitdepth_index;
 	int ret;
 
 	/* Write common registers */
@@ -914,6 +965,13 @@ static int ov9282_start_streaming(struct ov9282 *ov9282)
 		return ret;
 	}
 
+	bitdepth_index = ov9282->code == MEDIA_BUS_FMT_Y10_1X10 ? 0 : 1;
+	ret = ov9282_write_regs(ov9282, bitdepth_regs[bitdepth_index], 2);
+	if (ret) {
+		dev_err(ov9282->dev, "fail to write bitdepth regs");
+		return ret;
+	}
+
 	/* Write sensor mode registers */
 	reg_list = &ov9282->cur_mode->reg_list;
 	ret = ov9282_write_regs(ov9282, reg_list->regs, reg_list->num_of_regs);
@@ -1235,9 +1293,11 @@ static int ov9282_init_controls(struct ov9282 *ov9282)
 			  0, 1, 1, 1);
 
 	/* Read only controls */
-	v4l2_ctrl_new_std(ctrl_hdlr, &ov9282_ctrl_ops, V4L2_CID_PIXEL_RATE,
-			  OV9282_PIXEL_RATE, OV9282_PIXEL_RATE, 1,
-			  OV9282_PIXEL_RATE);
+	ov9282->pixel_rate = v4l2_ctrl_new_std(ctrl_hdlr, &ov9282_ctrl_ops,
+					       V4L2_CID_PIXEL_RATE,
+					       OV9282_PIXEL_RATE_10BIT,
+					       OV9282_PIXEL_RATE_10BIT, 1,
+					       OV9282_PIXEL_RATE_10BIT);
 
 	ov9282->link_freq_ctrl = v4l2_ctrl_new_int_menu(ctrl_hdlr,
 							&ov9282_ctrl_ops,
@@ -1319,6 +1379,7 @@ static int ov9282_probe(struct i2c_client *client)
 
 	/* Set default mode to first mode */
 	ov9282->cur_mode = &supported_modes[DEFAULT_MODE];
+	ov9282->code = MEDIA_BUS_FMT_Y10_1X10;
 	ov9282->vblank = ov9282->cur_mode->vblank;
 
 	ret = ov9282_init_controls(ov9282);